An introgression line population of Lycopersicon pennellii in the cultivated tomato enables the identification and fine mapping of yield-associated QTL.
An introgression line population of Lycopersicon pennellii in the cultivated tomato enables the identification and fine mapping of yield-associated QTL.
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作者：
Y. Eshed;D. Zamir
数量性状相关基因的定位方法已经有了很大的发展，但并没有伴随着新的种群结构的平行发展。我们提出了一个新的人口组成的50个渐渗系（ILs）起源于绿色水果种番茄和栽培番茄（CV M82）之间的交叉。每一株系都含有一个纯合的限制性片段长度多态性定义的L。pennellii染色体片段，并且这些品系一起提供了基因组的完全覆盖和一组与M82几乎等基因的品系。IL及其杂交种的田间试验显示，至少有23个数量性状位点（QTL）的总可溶性固形物含量和18个果实质量，这些估计是以前报道的估计的两倍，根据传统的作图人群。为了更精细地定位影响果实质量的QTL，将渗入片段重组成更小的片段，从而鉴定三个连锁基因座。至少鉴定了16个株重QTL、22个绿色果重百分比QTL、11个总产量QTL和14个总可溶性固形物产量QTL。果实和植株性状的基因作用主要是加性的，而野生种渗入的超显性（或伪超显性）检测产量。
Methodologies for mapping of genes underlying quantitative traits have advanced considerably but have not been accompanied by a parallel development of new population structures. We present a novel population consisting of 50 introgression lines (ILs) originating from a cross between the green-fruited species Lycopersicon pennellii and the cultivated tomato (cv M82). Each of the lines contains a single homozygous restriction fragment length polymorphism-defined L. pennellii chromosome segment, and together the lines provide complete coverage of the genome and a set of lines nearly isogenic to M82. A field trial of the ILs and their hybrids revealed at least 23 quantitative trait loci (QTL) for total soluble solids content and 18 for fruit mass; these estimates are twice as high as previously reported estimates based on traditional mapping populations. For finer mapping of a QTL affecting fruit mass, the introgressed segment was recombined into smaller fragments that allowed the identification of three linked loci. At least 16 QTL for plant weight, 22 for percentage green fruit weight, 11 for total yield and 14 for total soluble solids yield were identified. Gene action for fruit and plant characteristics was mainly additive, while overdominance (or pseudo-overdominance) of wild species introgressions was detected for yield.